Because space is limited in cities, particularly in the center of older cities, municipalities tend to use automatic, controlled public transportation systems for ground transportation.
Such transportation systems require a minimum of ground space, especially for turning.
Tramways are one such means of transportation, but recently there has been a more widespread use of automatic road vehicles guided by systems with various degrees of complexity, depending primarily on a guide rail which serves as a track for the guide wheels of the control mechanism.
Cities which already have public transportation dependent on roads or rails cannot afford to change their infrastructure, since often they have already made substantial investments in their transportation systems.
This invention proposes a positive solution to the problem of how to use existing structures for other types of transportation, particularly automatic ground transportation.
Patent Application No. DE 195 07 880 filed Mar. 7, 1995 by Societe Friedrich REMMERT (priority date Mar. 23, 1994) describes a guided railway travel system.
This system is used in various product storage applications, especially by displacing one or more crane structures.
According to this system, a carriage 1 holding the post 5 of a mobile unit is guided in movement along a rail 2 using supporting wheels 9.
Said supporting wheels move along an upper table in the rail. They support the weight of the carriage and its load. Two pairs of guide wheels (10, 11), front and rear, located on either side of the supporting wheel, move along adjacent pathways formed by the sides of the rail.
The supporting wheels are also surrounded by four lateral, rolling supports which guide the carriage.
The purpose of this invention is to provide a high degree of lateral stability for a heavy unit moving along a single rail.
The upper table portion of the rail is not used for guiding, but rather, exclusively for motion, with the motion being simultaneously guided by guide wheels contacting the lateral pathways.
Thus, motion and guidance along the same rail are inseparably associated and made possible by four guide wheels used in pairs, spaced apart from each other and located on either side of the support wheel, giving the carriage a high degree lateral stability.